For optical transmitting and receiving devices, a plurality of signals can be combined to be simultaneously transmitted or received over a shared medium. Multiplexing and de-multiplexing functions can be used for combining and separating individual signals for routing and/or interfacing with individual optical components.
An arrayed waveguide grating (AWG) is an optical component used to perform multiplexing and de-multiplexing functions for optical signals. An AWG typically includes one or more free propagation regions coupled to a dispersive waveguide array having varying lengths; these varying lengths are selected to result in appropriate constructive and destructive interference for light of certain frequencies transmitted from the free propagation regions, resulting in the combination or separation of optical signals. It is important to prevent noise having these same frequencies from passing through an AWG with low insertion loss, in order to eliminate this noise from being introduced into other components of an optical system.
Descriptions of certain details and implementations follow, including a description of the figures, which can depict some or all of the embodiments described below, as well as discussing other potential embodiments or implementations of the inventive concepts presented herein. An overview of embodiments of the disclosure is provided below, followed by a more detailed description with reference to the drawings.